Power supply



FIG. 1 is an isometric view of an ornamental design of a power supply showing our new design.

FIG. 2 is a front elevation plan view thereof.

FIG. 3 is a rear elevation plan view thereof.

FIG. 4 is a left side elevation plan view thereof.

FIG. 5 is a right side elevation plan view thereof.

FIG. 6 is a top elevation plan view thereof; and,

FIG. 7 is a bottom elevation plan view thereof.

The broken lines shown in FIGS. 1-7 are included for the purpose of illustrating environmental elements only and form no part of the claimed design. 

The ornamental design for a power supply, as shown and described. 